Automatic oil burner



Dec. 1, 1931. J oon AUTOMATIC OIL BURNER Filed Aug. 12,

1936 2 Sheets-Sheet 1 R o T. v m

Dec.- 1, 1931. J. GOOD AUTOMATIC OIL BURNER 2 Sheets-Sheet 2 Filed Aug. 12,

lNV NTOR Patented Dec. 1, 1933 WEN GOQD, E GARDEN CITY, NEW'YORK, ASSIGNOR TO GOOD INVENTIONS (70., OF N111)? YORK,'IN.'Y., A CORPORATION OF NEW YORK AUTOTIC OIL BEER Application filed. August 12, 1926. Serial No. 128,755.

The invention relates to the general class of oil burners, commonly referred to as domestic burners, although capable of use in other relations as will hereinafter appear. The objects of the invention are reliability and safety'of operation, in general, as well as many incidental objects which will hereinafter become apparent. The subject matter of this application includes an improved form ofburner operating in accordance with certain of'the general principles disclosed and exemplified in my prior application Serial No. 730,332, filed Aug. 6, 1924.

In the accompanying drawings, Fig. 1 is a side elevation with parts in Vertical section, illustrating the operating mechanism of the preferred form of the burner.

Fig. 2 is a cross-section on line IIII, and

Fig. 3 is a larger scale section of the entire mechanism in its full rate condition.

The apparatus shown comprises .a fire-pot 1 of any suitable design adapted to be supported in the combustion space of a boiler or a house-heating furnace of any type, and a frame or casing 2 supported on legs outside of the furnace, and containing the fuel and air ducts and the control mechanism whichis immediately pertinent to the regulation of the fuel. This control mechanism is desirably supported on a tray 3 which is removable endwise, like a drawer, from the end of the casing 2 for inspection purposes. The top of the casing supports the operating electric motor 4 and a fan blower driven thereby, which delivers low pressure air into the top of the casing 2 and through the latter to the pot and combustion space. The motor also drives a small air pump 5 which supplies higher pressure air for spraying the fuel into the fire pot and this pump also furnishes the suction necessaryfor operating a so-called vacuum feed tank 6 by which oil is drawn in small quantities from a remote source, as for instance, a buried tank outside the building, and delivered by gravity to the burner mechanism. The electric motor 4, in the present case also drives an electric generator 7 to furnish current to the spark plug fer ignition, although other means of ignition may used if desired. The general organization of parts above referred to is already known to this art.

Liquid fuel from the elevated feed tank 6 passes by way of shut-off valve 8 and pipe 9 to the entrance valve 10 of a control box 11. This valve is operated by a lever -12 and the lever is operated by a diaphragm or metallic bellows 12, but the operation of the lever by the bellows is intended to be blocked at certain times by the action of a hydrostatically controlled hook 14. This book is arranged to be operated by a float-ball 15 which normally floats on a body of oil in the bottom part of the control box. Fig. 1 shows the float-ball in its elevated position and its hook 1 1 engaged with a roller stud 1 1 on the lever 12, holding the latter against movement by the diaphragm or bellows mechanism. This is the stand-by position. The outside of the bellows is enclosed in an airtight housing 13 wherein it is subject to the pressure of air furnished by the air pump 5 for spraying the fuel. Such air is delivered by the pump through pipe 5 to an air receiver 16 and thence by an S-shaped pipe 17 to a T fitting 18. One arm of this T connected through a restricted opening (18 Fig. 3) with the bellows casing 13 outside of the bellows, so that the air pressure is efi'ective to collapse the bellows and thus operate, or exert its force upon, the lever above referred to. The other arm of the T 18 conducts the air-flow by pipe 19 to the air jet of a double oil-jet spray nozzle 20 and in aspirating relation to the oil ducts-therein. The two oil duct orifices in this nozzle may be arranged in any suitable manner so that the air-jet will deliver the oil therefrom. One of them which has its outlet immediately next to the air-jet, is smaller than the other and is connected by pipe 21 with the bottom of the oil reservoir space in the control box 11. The other oil-jet is connected by pipe 22 with the upper part of the same reservoir and this orifice is larger and intended to deliver oil at a much higher rate of supply than the other one.

When the burner is not in action, the oil level in the control box is about as indicated in Fig. 1, the ball-float hook 14 is locked to the lever 12 and the oil entrance valve 10 thereby held closed. When the motor 4 is started, air pressure from the pump 5 is communicated to the bellows casing 13 but cannot actuate" the bellows because, as just stated, the lever 12 is locked by the hook. Such pump air, however, operates the sprayer 20 producing an atomized spra of liquid fuel in the burner head 23. The uel for this spray is supplied by the smaller oil-jet connected as above stated by pipe 21 to the bottom of the oil reservoir. The aspirating effect of the air-jet does not draw oil through the other oil pipe 22, because at this time the oil level in the control box 11 is lower than the point of connection thereto of that pipe. Thus when the motor 4 is fi rst started, the spray nozzle 20 produces a spray of fuel derived entirely from the control box through the pipe 21. This spray is ignited by the spark plug 24, producing a flame which extends more or less into the'fire pot, combining therein with some of the com'bustion supporting air furnished by air blower 4 which air passes to the fire pot through and around the burner head 23. The rate at which fuel is supplied to this flame is relatively low, in fact no greater than sufiicient to insure reliable ignition and provide for some warming up of the fire pot. The i ition of this small amount of fuel, in a position where it is surrounded by a relatively very large volume of air, furnished by the blower, constitutes an important factor of safety in the operation of the present burner, inasmuch as it thereby becomes impossible for an explosive mixture to be formed in the combustion space, except in amount so small as to be negligible in effect. The air supply furnished by the motor blower is much. in excess of that which would combine with the delivery from the small oil jet to make an explosive mixture capable of injuring the boiler'or furnace.

During the low rate of operation of the double-jet sprayer 20, just described, the 011 taken from the reservoir in the control box 11 gradually lowers the level in the latter until at a certain point the float-ball hook releases the lever 12, this lever being already under the pressure of the air acting on the bellows 12', immediately swings to its other position, shown in Fig. 3, opening the fuel entrance valve 10 whereupon fuel from the elevated vacuum tank pours into the control box through the piping already described, immediately raising the oil level therein up to or slightly above the outlet to pipe 22 and thereupon both oil jets in the sprayer 20 and both pipes, 21 and 22, become active in furnishing oil to the fire-pot, and the resulting flame in the fire-pot is thereby greatly enlarged constituting the normal combustion. The air supplied by the motor blower is now suited to the rate of supply of fuel but is desirably somewhat in excess of that required for theoretically complete combustion. Thus aseasea level to drop sufliciently to release the hook.

14 and this can, of course, be made as short or as long as desired. While it is preferred to supply the fuel by the air-aspiration method, it will be apparent that the advantages above described will be secured by any other method.

When the fuel entrance valve has been opened, the ball float 15 again immediately rises, but its hook 14 cannot re-lock the lever 12; it merely bears against the roller stud 14 by its upstanding lip as indicated in Fig. 3.

The spark plug 24 is connected by a wire 25 to the generator 7 or to such other source of ignition current as may be employed, and is arranged to be rendered dead or inactive before the sprayer begins to deliver its high or full rate supply, so that there will be no possibility of a spark occurring whenever the full rate fuel supply is in o eration. This is accomplished by means of t e small plunger 26 actuated by the free end of the fuel lever 12 when the latter is released by the ball float. This plun er rises into contact with the terminal of a ranch 27 of the ignition wire thereby grounding the latter through the metal of the burner structure. Such grounding occurs immediately on the release of the fuel lever 12 and before the oil incomingv through valve 10 has raised the level in the control box to a point high enough to begin the higher rate delivery through the sprayer pipe 22. Where other types of ignition are employed the lever .12

is adapted also to control the same with the same effect.

When this higher rate has begun, the burner is in its normal combustion condition, burnin the maximum amount of fuel of which it is capable and it will obviously continue in this condition as long as the motor 4 is ke t in operation. When the latter is stopped the immediate failure of air pressure in the casing 13 results in the reverse movement of the fuel lever 12, immediately closing the fuel entrance valve and shutting ofi further supply of fuel to the control box 11. This movement of the fuel lever 12 also results in the lowering of the roller stud 14 to the position shown in Fig. 1, whereupon the float rises and the hook 14 once more engages the roller stud. The elevation of the ball float causes a lowering of the oil level in the reservoir and these parts are so proportioned that the oil level at this time drops below the outlet of pipe 22, thus simultaneously depriving that pipe of fuel. This results in an immediate discontinuance of the main or high fuel rate and, while the low rate fuel pipe 21 is still filled with oil, there is no delivery therefrom by the sprayer 20 and hence no after-burning in the fire pot. It is a common objection in automatic oil burners that on stopping the driving mo-, tor, there is a residual deliver of oil into the fire-pot which is objectiona le.

On the next operation of the motor 4, the same cycle will be repeated, i. e., first, a small and safe flame, surrounded by much air, will be produced during the initial low rate delivery of sprayer 20 and then, after an ap propriate lag interval, the spark plug or other igniter will. be out out and the fuel rate will be increased to its normal value.

As a precaution against the delivery of fuel into the fire-pot from the main supply when ignition, for any reason, has not occurred, a small thermostat 28 is located in the burnerhead 23. This thermostat may consist of a simple piece of metal which at normal temperature opens the passage through-a vent passage 29 connected to the bellows casing 13 by pipe 29 but when expanded by the heat of the low rate flame closes such vent. If ignition has not oc-v curred, the vent 29 is left open and the air acting on the bellows in casing 13, through the restriction '18 of the T 18, wlll not bulld up suflicient pressure therein to be effective,

* and consequently, the fuel lever 12 will not be operated to open the fuel entrance valve 10. The burner will thus cease operating as soon as the small supply of oil in the bottom of the control box has been consumed. The

cally under the control of a thermostat or the like, suclr as indicated at 30, and which is situated in the place where the temperature Is to be controlled and as represented in Fig. 1. It will be understood also, and will be apparent that the principles above explained can be incorporated in apparatus of widely differing mechanical organization from the specific structure taken for illustration, and that there is no intended -limitation to such mechanical embodimentexcept as defined by the claims hereto appended.

Having .now described my invention, I claim 1. Oil burning apparatus comprising means for effecting a preliminary delivery of fuel when the operation of the apparatus is initiated, an igniter for the fuel so delivered, a main fuel supply and means responsive to the combustion of said preliminary delivery forinitiating the operation of said main fuel supply and rendering the igniter inactive.

2. Oil burning apparatus comprising means for effecting a preliminary delivery of fuel when the operation of the apparatus is initiated, an igniter for the fuel so delivered, a a main fuel supply, an' air pump system for effecting the delivery of fuel by way of said main supply, a valve operated by the heat of combustion of said preliminary delivery for rendering active said system and means for rendering the igniter inactive in response to operation of said valve.

3. Oil burning apparatus comprising means for effecting a preliminary delivery of fuel when the operation of the apparatus is initiated, an igniter for the fuel so delivered, a main fuel supply, a valve normally preventing the operation of said main supply and means responsive to the combustion of said preliminary delivery for controlling the operation of said valve and rendering the igniter inactive.

4. Oil burning apparatus comprising means for delivering air and oil to a place of combustion initially in non-explosive proportions and subsequently in substantial accordance with normal combustion requirements, an igniter operative only while such non-explosive proportions obtain in the combustion space and means responsive to the combustion of said first mentioned delivery for initiating the subsequent normal delivery.

5. Oil. burning apparatus comprising in combination with an igniter and means for feeding fuelto a place of combustion, a main oil supply, a limited starting source. whereby the oil is initially delivered by said feeding means at a diminishing rate, means responsive to the combustion of the oil from said limited source for initiating the operation of said main supply and means for rendering the igniter inactive prior to the'operation of the main supply.

6. Oil burning apparatus comprising an operating motor, an air blower, two-rate fuel spraying mechanism and means for controlling the duration of the operation thereof at its lower rate comprising an oil reservoir having a fuel entrance valve and a fuel operated member controlling the time of opening of said valve.

7. Oil burning apparatus comprising motor-driven means for supplying an air flow suited for combustion at the normal rate of the burner, fuel sprayer mechanism adapted to deliver liquid fuel into said air flow, means whereby said mechanism initially delivers the fuel into said air flow at a low rate suitable for maintaining a small flame, a reservoir to supply such low rate delivery and a hydro statically operated device for said reservoir livery suitable formaintaining the normal flame. i

8. Oil burning apparatus comprising a therinostatically-controlled operating motor, means operated thereby for supplying liquid fuel at low and high rates, said means com prising a pressure-operated member, and fuel-controlled means for blocking the operation of said member.

9. Oil burning apparatus comprising in combination with an igniter and means for feeding fuel to a place of combustion, a main oil supply, a limited starting source whereby the oil is initially delivered at a diminishing rate and mechanism controlledby the depletion of said limited source for controlling said main supply and the activity of the igniter.

10. Oil burning apparatus comprising means for establishing a flow of air, means for delivering fuel to said flow initially at a low rate for ignition purposes and mechanism controlled by the depletion of the initial fuel supply for delivering fuel thereto at a higher rate for normal burning.

11. Oil burning apparatus comprising means for effecting a preliminary delivery of fuel when the operation of the apparatus is initiated, fuel ignition means, a main fuel supply, controlling means dependent on the ignition of said preliminary delivery for initiating the operation of said main fuel supply and connections whereby said initiating means also operates to render inactive the fuel ignition means. I

12. Oil burning apparatus comprising a combustion space, an operating motor for supplying fuel thereto initially at a low rate and later at a higher rate, an electric igniter and means rendered active'by the operation of the-low rate for bringing on the high rate, after an interval, and de-energizing the igniter.

l3. Oii burning apparatus comprising means for delivering air and oil to a place of combustion initially in non-explosive proportions and subsequently in substantial accordance with normal combustion requirements, a limited source of supply for the initial and a main supply for the subsequent fuel delivery, an igniter and means responsive to the heat of combustion of said initial delivery for initiating the subsequent dclivery and rendering the igniter inactive.

14. Oil burning apparatus comprising means for delivery air and oil to a place of combustion initially in non-expiosive proportions and subsequently in substantial accordance with normal combustion requirements, igniter means responsive to the combustion of said first mentioned delivery for initiating the subsequent normal delivery, and rendering the igniter inactive.

l5. Oii burial: apparatus comprising means for cont ously delivering oil to a place of combustion, means for delivering thereto a quantity of air sufiiciently in excess of the combustion requirements of said oil to produce a non-explosive mixture, means for effecting the delivery of additional oil to conform the mixture proportions to normal combustion requirements, means for delaying-the operation of the latter, an igniter and means responsive to the ignition of said non-explosive mixture for bringing on said additional delivery.

16. Oil burning apparatus comprising means for initially effecting delivery of air and oil to a place of combustion in proportions to produce a lean, non-explosive m1X ture therein, an igniter and means responsive to the combustion of said oil to conform the air and oil proportions to normal combustion requirements.

17. Oil burning apparatus comprising means for initially effecting delivery of air and oil to a place of combustion in proportions to produce a lean, non-explosive mixture therein, an igniter arranged to ignite said oil'prior to its admixture with said air in the combustion space, and means responsive to the combustion of said oil to conform the air and oil proportions to normal combustion requirements.

18. Oil burning apparatus comprising means for initially effecting delivery of air and oil to a place of combustion in proportions to produce a lean, non-explosive mixture therein, an igniter arranged to ignite said oil prior to its admixture with said air in the combustion space, a thermostat located for operation by the combustion of said oil, and means for conforming the air and oil proportions to normal combustion requirements, said last mentioned means controlled by the thermostat. I

in testimony whereof, I have signed this specification,

JOHN GOOD. 

